Emergency Management - Fall 2008 - (Page 26)

chance in the life of a 30-year mortgage that the levee is going to be topped and that there’s going to be some sort of disaster,” Galloway said. The term “100-year-flood” is misleading and not applicable anymore, experts say. “I think we’re really overstating; I don’t think those terms are useful,” Criss said. “We need to acknowledge that the language is flawed and there are better approaches.” Galloway said the 1994 report called for 500year protection, but no one has been willing to buy into it. “The Corps of Engineers said by 2011 they’re going to have 100-year flood protection,” he said of the rebuilding effort in New Orleans. “Aren’t they lucky? They’re still in huge danger.” “We not only have more floods and higher flood stages, but they occur at every time of the year now. Basically we have a more chaotic river than we had historically. It’s not the controlled system we think we’re trying to make. We delude ourselves with these concepts.” — Bob Criss, professor, Washington University Big Risk Besides New Orleans, California probably faces the biggest risk of a catastrophic flood. Developers there continue to build in floodplains behind questionable levees. “It’s simply because that’s where the money is and that’s where developers go,” said Jeff Mount, geology professor at the University of California, Davis and director of the Center for Watershed Sciences. “It’s more subsidized bad choices.” California is searching for ways to strengthen deteriorating levees that protect populous areas. In the Natomas community in Sacramento County, a levee breach could put more than 11,000 homes 20 feet underwater. The state recently passed a $4.1 billion bond measure to shore up weak and eroded levees. But that’s not enough, Mount said. The 2006 bond measure amounted to patching an old tire, he said, and the state’s efforts have progressed little since then. “The tire’s bald, all worn out and wobbly, and the rim is rusted,” Mount said. “Right now we’ve brought the car into the shop and we’re all standing around looking at the tire.” Mount said patching the levees is necessary. “It’s an emergency.” But he said those repairs are merely a Band-Aid. As in flood management elsewhere in the United States, there are a number of solutions, all of which comprise a balanced approach that experts say is necessary. Mount said truly fixing the levees might mean relocating them or removing them altogether, letting water spill over onto farmland to ease pressure downstream. “As long as we’re primarily agricultural, that’s a viable alternative to creating fortresslike levees, which are so bloody expensive and environmentally damaging.” A proposed Auburn Dam along the American River above Sacramento would help, but is expensive and environmentally harmful. “On a purely economic basis, it doesn’t work,” Mount said. “And where are you going to mitigate the drowning of 37 miles of river to the [Sierra Nevada]?” During the Missouri floods this spring, levees in the upper watersheds failed, which ironically Flood waters in Arkansas from the Cache River, a tributary of the White River, ﬂooded farmland and houses throughout the region in March 2008. This is Highway 33. saved the communities downstream from being inundated. “The urban areas owe their livelihoods and safety to the fact that their upstream neighbors absorb the shocks of the very large floods,” Mount said. “It’s the same as a levee setback, in a sense. The levee breaks, takes the top off the hydrograph and reduces the stage downstream so the suffering of a few is the salvation of thousands.” It could be a lesson in flood management. Instead of flushing water downstream as quickly as possible, keep it in the upper watersheds longer with detention areas, by setting back levees or by flooding farmland. “It’s an excellent idea, but it’s turned out to be damned hard to do,” Mount said, principally because the United States is a nation that puts private property rights as highest values. But the concept has worked in the Pacific Northwest and Tulsa, Okla. Retaining Water Parts of the Pacific Northwest are experiencing more rain and less snow, which means more runoff in the spring and less water during the summer. It’s essential to find ways to keep the water where it falls for a longer period of time. That was accomplished with retention ponds in Oregon, where a stream called Buck Hollow — a tributary of the Deschutes River — used to flow intermittently. When it did flow, it was big, brown and laden with silt. Farmers along the stream built detention ponds, which keeps the water longer in the upper levels of Buck Hollow. The result is a consistent flow of cooler, cleaner water for fish and more water on the farmers’ fields. Freitag said it’s important to understand that flooding is natural, even beneficial. Prior to the 1980s, Tulsa was continually hit with severe floods. During a 15-year stretch, the federal government declared Tulsa County a flood disaster area nine times. That’s history. Since 1986, the area hasn’t had a major flood. “They’ve removed homes in the floodplain, they’ve made large detention areas,” 26 PHOTO BY JOCELYN AUGUSTINO/FEMA

Table of Contents Feed for the Digital Edition of Emergency Management - Fall 2008

Emergency Management - Fall 2008 Contents Contributors Editor’s Letter In the Field Deep Freeze EM Bulletin Major Player In the News Uncharted Waters Bio-Sensing Bluegills Joint Accounts Education Directory Degress of Change Triage in 3-D Products Eric's Corner Last Word

Emergency Management - Fall 2008

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